Process of recovering copper from copper-bearing solutions.



No. 890,887. PATENTED JUNE 16'', 1908. L. AMENABAR. PROCESS OF REUOVERLNG COPPER FROM COPPER BEARING SOLUTIONS.

APPLICATION FILED NOV. 4, 1907.

w; b1 ease:

' and the copper recovered therefrom.

and space required in a plant unrrnn sraras LUIS AMENABAR, or COQUIMBO, CHILE.

PFZGCESS OF REQOVEBING COPPER FROM COPPER-BEARING SOLUTION S No. en ear.

Specification of Letters Patent.

Patented June 16, 1908.

Application filed November 4, 1907. Serial no. 400,518.

To all whom it may concern:

Be' it known that I, LUIs AMENABAR, of Coqunnbo, in the Province of Coquimbo, Chile, have invented a certain new and useful Improvementin Processes of Recovering Copper from Copper-Bearing Solutions; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the figures and letters of reference marked thereon.

This invention has for its object to provide an improved process of recovering copper from the lixivium or liquor rived fronr a leaching, lixiviating or similar process, in which the copper content of the ore is taken into solution.

In accordance with present prevailing commercial practice, it is customary to run the solution derived from the lixiviation plant into suitable tanks, usually of large aggregate capacity and to precipitate the copper by means of iron in a metallic state and usually in the form of scrap iron. The operation of precipitation requires from two to three days time and results in a large waste of the iron, to say nothing of the large tanks having any considerable capacity.

In accordance with the present invention the liquor containing the copper in solution especially a sulfuric solution is treated electrolytically in relatively small volumes or units in a circulating system or systems, the electrolytic action being so regulated that the copper is precipitated in a non-coherent,

granular or flocculent form without destroying or requiring that the electrodes between which the electric current is caused to flow shall be changed or renewed and the result being that the precipitate is carried along with the solution. and separated therefrom at a succeeding point in the system.

Generally speaking, an apparatus for carrying the present process into practice preferably embodies two storage reservoirs of relatively large capacity, one for the liquor from the lixiviation plant and the other for the liquor which has already been ted is der any circumstances the apparatus embodies one or any desired number of circulatingsysterns, each comprising an electrolytic tank, a separating means for the copper precipitated by th'e electrolytic action, suitable pi mg and means whereby the liquor may e circulated through the electrolytic tank and discharged into one of the store e tanks from which it may be conveyed to t is lixiviation plant. p

In the accompanying drawings*Figure 1 is a diagrammatic illustration of an apparatus with which the present invention may be carried into practice, a series of three circulating systems being illustrated. Fig. 2 is a perspective view of an electrolytic tank such as is preferably employed in carrying the invention into practice.

In said drawings, the letters A and B indicate the storage tanks; tank B being adapted to receive the li nor from the lixiviation plant and the ta A to receive the liquor from which the copper has been recovered and which may be returned to thelixiviation plant. From the tank B the copper charged. iquor is conveniently drawn through a pipe 0 and stopcocks c to one of the tanks l), preferably of relatively small capacity and forming part of the circulating system to be now described. From tank D the liquor passes through a pipe 11 ha ing a regulating cook 11 therein, to one end of an electrolytic tank or tanks E, a discharge c controlled by a valve 6 being provided at the opposite end of the electrolytic tank for permitting the liquor and precipitated copper to pass into a settling or separating tank F. The overflow from separator F passesinto a container G from which it may be pum ed or conveyed back to the tank 1) to comp etc the circulating system or, if sufiiciently treated, it may be directed into the tank A. As illustrated, a pump H is provided in each circulating system with suitable piping indicated at it for conveying the liquor from the container G to tanks D or A, as desired, the branch pipes leading to said tanks being controlled by valves h. I

Each of the electrolytic tanks is preferably provided with a plurality of anode and cathode plates K, best seen in Fig. 2. Said anode and cathode plates are arranged to alternate and in the preferred construction are supported on the conductor bars L by which current is conveyed to the1n,it being understood, of course, that the electrodes are insulated from the conductor bars alternately at opposite ends of the tank, whereby the'current is separating means or, when sufiicientlytreated caused to traverse the liquor contained in of employing other means save possibly the the tank between the electrodes. trodes are preferably arranged in multi le in each tank and Where a series of circu ating systems are employed it is referred, but not considered to be essentia, that the tanks should be arranged in multiple with each other in the-sup ly circuit. The multiple arrangement is ilustrated in Fig. 10 f the accompanying drawings, where M indlcates agenerator and N circuit wires.

In operation, the desired quantity of cop'-' per charged liquor is run into the tank D and from the latter it is allowed to flow under .valve regulation to the electrolytic tank E where precipitation takes place, and from the latter the liquor and precipitate together pass on to the settling tank F, where the precipitate is deposited and may be removed by approved means, such, for instance, as a foraminous shovel. The liquor partially or whollyfree from copper,passes'on to the container G and from the latter back to the tank D. The circulation of the solution in the system is continued until the whole xantity ciently diverted to the storage tankA for subsequent use.

Demonstration on a large scale in practical work, has shown that practically complete precipitation of the copper-in a given charge trodes, washing maybe effected in one hours time, but 1n order to prevent. the copper from c'ohering or adhering to the cathode as it does in ordinary refining o erations, the current employed must be 0 a sufficiently high density to precipitate the copper in a spongy, granular flocculent or non-coherent form. Althou h the density of current employed may e varied betweenwide limits, practice has demonstrated that withv a current of 200 amperes and a proximately 5 volts per square foot of e ectrode, gives excellent results, both as to economy in time and current consumption. Practice further demonstrates that an amperage below 25 or 30 amperes per'square foot' of. electrode surface wil not give satisfactory results.

Under, the required conditions any deposit on the cathode will beof such nature that it may be readily dislodged by shaking the electrolyte or by a light scraper ap lied manually or otherwise and when dislo ged such precipitatewill pass out of the electrolytic tank with the liquor. In practice the circulating system serves to carry all of the preci itate to the separator and to further this particular end, it is preferred that the liquor should be supplied to the electrolytic tank at one end, and discharged therefrom at the opposite end, the flowing liquor thereby s'ervin as the means for conveying or carrying off t 1e precipilate and thereby avoiding the necessity The el'ec them, circulating the elec occasional attention of an attendant to apply alight cleaner to the sides of the cathodes.

It is important in order to give the best re sults and to provide a permanent organization in so far as the anodes and cathodes are concerned that the anodes employed be of an insoluble material, such as lead or carbon, thou h anyinsoluble conducting material is suita le. lead or other metal. The use of insolub e anodes is advantageous in that they do not reuire constant replacementand, further, by

t ieir use, the solution containing considerable sulfuric acid is not vitiated but is preserved for subsequent use in the lixiviation of new ores. The electrolytic tanks should be s'u ported on insulators to prevent current lea age and the tanks D andGit is obvious should be of such capacity that any differences between the rapidity of circulation in the two sides of the system will not cause an overflow.

Having thus described my invention, what I claim' as new, and desire to secure by Letters Patent, is:

1. The process of recovering copper from a co per bearing solution whlch consists in su ecting the solution to the' electrolytic action of a current of great density while in a circulating system in which the solution is brought into and removed from the field of electrolytic action a number of times.

2. The process of recovering copper from a copper bearin solution which consists in repeatedly circfiatin'g the solution through an electrolytic tank and separator and subjecting the solution to the electrolytic action of currents of great density whereby a non-coher: ent precipitate of copper is formed and carried to the separator by the circulating solu tion.

3. The process of recoveringcopper from a copper bearing solution which conslstsin suplying the solution to one end of an electroytic. tank, discharging the same from the bottom at the opposite end and subjecting the solution to the electrolytic actionof cur- The-cathodes may be of co per,

ice

rents of great density whereby the copper is preci itated-in non-coherent form and is car- -ried rom the tank with the solution.

4. The continuous process of recovering copper from a copper bearing solution which consists in'subjectlng the same to the electrolytic action of currents of great densit between an insoluble anode and metal cat ode,

discharging the non coherent preci itate from the electrolytic field as forme finally separating the solution and precipitated copper.

5. The continuous process of recovering copper from copper bearing solution which consists in subjecting the same to the elecand trolytic action of currents of great density I between an anode which is insoluble and a cathode whereby a non-coherentprecipitate is formed and in discharging the solution and precipitate together from the electrolytic ield.

6. The process of recovering copper from a copper bearing solution which consists in circulating the solution more than once through a circulatin system containingin succession a field of electrolytic action, and a separator for the precipitate, subjecting the solution in said field to the action of currents 10 of great density to forni a mechanically subdivided precipitate and finally dischargi the liquor from the circulating system ar i removing the separated precipitate.

LUIS AMEN ABAR. Witnesses:

ELIZABETH GRIFFITH, THOMAS DURANT. 

